Automobile crashes pose a serious public health problem, and drivers with aging and age-related neurological and medical disorders are at increased risk for crashes due to cognitive impairment. Specific effects of cognitive disorders that increase the risk of driver crashes, such as impaired decision-making, can be assessed safely and in detail, under standardized, controlled circumstances in a virtual environment. The long-term objective of this project is to develop low-cost PC-based virtual environment software for assessing fitness-to-drive of cognitively impaired licensed drivers. The investigators draw from multidisciplinary expertise in computer science, neuroergonomics, and public policy. The proposed software product comprises an innovative suite of tools for testing cognitive functions related to the ability to perform driving-related tasks. The graphical component of the software uses a non-photorealistic representation of 3D virtual space and provides rich visual and pictorial motion cues on a standard computer screen without the cost and potential discomfort associated with simulations implemented on large "immersive" displays. Specific candidate scenarios implemented are theory-based and aimed at localizing cognitive errors in the driving task. The work of SBIR Phase I will include research, implementation, and experimentation that will demonstrate feasibility of the long-term objective. Specific Phase I work includes: (1) Create two proof-of-concept software tests: for Go/No-Go decision making, and for susceptibility to distractions ("mudsplashes"); (2) Conduct clinical evaluations of the tests in neurologically normal and cognitively impaired licensed drivers; (3) Determine an appropriate candidate test set for the full suite, to be prototyped, refined, and fully assessed in Phase II. The suite of tools will ultimately address critical aspects of the driving task including navigation, sign/landmark recognition, intersection and rear-end collision avoidance, and multitasking. The suite of tools is expected to be more flexible and cost effective than currently available driving simulator tools and more effective at predicting fitness-to-drive than standard ("paper and pencil") neuropsychological tests. The resulting virtual environment software tools could benefit society by providing accurate, fair, affordable and accessible tools for evaluating drivers with defects in cognitive abilities that are critical to safe automobile driving.